A few days ago, media reports on the net, come as summertime high temperature, appear without Xi Taihu many flaxen La Zao is flush phenomenon, spread all over lake face ten kilometers, caused the high attention of social all circles.
The staff member is salvaging La Zao to suffer the person that visit to offer a plan
How is flaxen La Zao formed? Besides concern with high temperature, does with the environment in water pollution matter? Too where is the difficulty that the lake administers after all, what technology was used on processing at present, whether can you popularize in the round? Do not have stannum to will take what significant step again, will ensure " safe estivate " ? For this, reporter of daily of science and technology interviewed relevant section and expert.
Too lake water system is in eutrophication condition all the year round
The reporter understands from bureau of irrigation works of the city that do not have stannum, the La Zao that media reports on the net is flush phenomenon, exist really. But the lake face of the overflow of the heave that lie between green jade of the one bank that shows in the picture, not be a lake, the pond that pass is administered via professional corporation inside the bank however. Accordingly, caption not substantial problem, also do not have representative. But this year, as a result of recently weather is torrid, already produced water of local blue green alga really China. Current, had adopted without stannum urgent answer measure, main and safe estivate.
Deng Jiancai of deputy researcher of geography of Nanjing of Chinese Academy of Sciences and laky institute introduces, blue green alga is former nucleus biology, call La Luzao the bacterium again, already existed 3.3 billion years on the earth, it is the the simplest, most primitive kind in all alga biology, also be appear on the earth the earliest, distributing the light with the widest, the strongest adaptability adds up to autotroph.
Blue green alga water China is to point to fall in appropriate outside ambient, the alga such as blue green alga, green alga, diatom becomes the advantage in water system to plant group, it is after a large number of breed inside short time from inside water rise arrives water meter face, or because the action of wind is in local district to gather in great quantities,be, make water system presents a kind of appearance of blue or green.
Growth period of blue green alga is briefer, whole lifecycle can divide a level: Growth period, fastigium, become feeble and die period. Blue green alga passes photosynthesis cell hyperplasia inside growth period, the alga gross mushroom of water column body; Density of fastigium blue green alga is achieved the biggest, occurrence gasbag and glue scabbard, rise plays in condition of appropriate atmosphere, hydrology, surface shows bright green; Become feeble and die period La Zao begins cankered degradation, after blue green alga becomes feeble and die 5 days, turn into olive, buff turns into after becoming feeble and die 22 days, white turns into after becoming feeble and die 50 days.
"Too the lake appears suddenly water China is eruptive be not alga to grow quickly continuously inside short time be caused by, already existed however, dispersive the alga rise in water system, gather, migratory the process that is place of people naked eye to see to surface. Too the lake appears without stannic water area flaxen La Zao gathers in surface, the system of incomplete of blue green alga that there had been a large number of beginning that become feeble and die in the La Zao that indicates rise, need to be salvaged in time, reduce oxygen of water system bad news and poisonous and harmful material to release. " Deng Jiancai says.
Look in Deng Jiancai, too lake blue green alga besides concern with high temperature, still having affinity with pollution of the environment in water. Blue green alga of water China forming wait for place of element of a lot of environment to cause by the physiology characteristic of alga itself and temperature, illumination, nurture and other live thing commonly. Too the concern with chroma of lake blue green alga and particular existence of water system contaminant, this kind of relation has otherness on the space.
Environmental engineering pharmacy of institute of technology of Changzhou project profession and Dr. Yuan Lijuan red thinks, too coastal industry and agriculture produces the lake special develop, the pollution that will develop because of economic high speed and arise for years is add accumulate, make too the lake is silty by much nitrogen, phosphor is contained a lot ofin pledging, too lake water system is in eutrophication condition all the year round, this is too the germ with lake eruptive blue green alga.
It is what every year to always break out in the water area that do not have stannum
Enter every year after May, to having stannum for, it is annual " final examination " . So, for what too can lake blue green alga always be in is concentration of the water area that do not have stannum eruptive?
Too lake on face of ten kilometers lake, stretch to the horizon of blue green alga.
Chief tells a reporter related bureau of irrigation works of the city that do not have stannum, because layer of blue green alga can be below wind- driven action,this is, alee place gathers. And having stannum is to be located in too Hubei ministry, the summer too southeast wind of lake be current, be in next wind direction without stannum, whole too the La Zao that the lake grows all was blown too the lake does not have stannic water area, together with is continuous without stannic lake water front labyrinthian, the numerous lake bay such as lake of bridge of bay of lake having tribute, plum, Zhu hill lake. The landform landforms with these lake changeful bays makes Yi Jin of blue green alga goes out hard, also make become without stannum too lake blue green alga is eruptive " heavy disaster area " and " advocate battlefield " .
2007, do not have stannic happening " water supply crisis " , it is namely the lake happens to float place is brought about inside limits of water intake of works of Na Quan water. Lake extensive is to point to system of laky eutrophication water in alga many and eruptive, accumulation is mixed after death, meet requirement of appropriate hydrology, atmosphere, the organic matter in bottom mud is in anoxic issue generation biochemistry response with condition of oxygen of be disgusted with, release the gas such as sulfide and firedamp, form brown black to accompany fetid sewage group.
Deng Jiancai tells a reporter, of blue green alga of plum bridge bay grow to be put in phosphor to restrict not only, and the azotic limitation with apparent existence; Too lake western bay of bayou area, Zhu Shan and algae of tribute lake bay grow to basically suffer phosphor to restrict; Dong Taihu blue green alga grows not to get NP concentration control. Accompanying water system eutrophication and NP pH indicator are elevatory, hyperplasia of Dong Taihu alga is not apparent, and plum bridge bay and western the La Zao in system of bayou area water grows rate general increases apparently, because of this alga water China is in these two area are more serious. Current, the main put forth effort that blue green alga administers is nodded or ought to the aggrandizement control to NP bear.
Reporter from the municipal government that do not have stannum relevant section understands, since 2007, salvage La Zao without stannum as processing too the lake is the directest, most environmental protection and very significant step, mix with safety of give attention to two or morethings efficient for the target, in the edge too setting of section of volume of Yi Ju of lake blue green alga is fixed salvage nod and salvage platform, reasonable configuration mechanization salvages a boat, use motor-driven is salvaged and secure the means that salvages photograph union to salvage La Zao. This year, installed 81 to secure in all without stannum salvage a dot.
Rely on onefold technology to have processing effect hard
Should say, 2007 too the lake does not have stannum " water crisis " later, in national water system pollution is administered great and special with province, city various local government too below the joint efforts with lake special processing, too the water quality improvement of the lake and research and development of zoology rehabilitate technology obtained great progress, a lot of technologies achieved international advanced level, be in too the demonstrative project that lake area made a success.
The reporter understands, of the one bank that everybody sees from the net lie between two pieces of different pictures, it is chroma of the alga in system of two kinds of water has bigger difference be caused by. Test division surface shows blue, show chlorophyll A chroma is smaller. Processing of its blue green alga basically is the integrated technology method that uses water quality improvement and zoology rehabilitate, formed a grass that is main and primary producer with aquatic vegetation ecosystem, better land restrained alga, water system has taller diaphaneity.
"Current, the bottleneck that processing technology popularizes in the round basically has two, depend on cost on one hand, depend on the natural feature with large laky shallow water and service function on the other hand. Dong Taihu water front is labyrinthian, lake bay is more, be development of heavy water vegetation and technology of zoology adjusting control carry out carry in all good condition. Xi Taihu water front is suitable straight and bank bank is cement a low stone wall built along the water's edge to protect an embankment more, lake range is wide, blast billow is eroded to lake bottom and wave is strange spread pair of lake bank base draw out corrode serious, the difficulty that increased lakeside wet ground and lake body zoology to rebuild greatly. " Deng Jiancai says.
Deng Jiancai suggests, too the lake is located in economy to develop, the long triangle area with concentrated population, improve lake style water quality to be released besides the source inside control, the key depends on catchment polluting processing, cut down a lake to pollute bear further from fountainhead. In the meantime, should solve La Zao from root eruptive problem, should establish treats alga first the concept of prevent floods by water control, severe accuse contaminant to enter a lake, mouth of the wadi that enter a lake creates zoology buffer; At the same time silt of fixed Qing Dynasty, cut down inside source pollution, restore to purify ability naturally stage by stage, reduce La Zao's generation from fountainhead.
Guo Guozhong of our newspaper reporter
Wu Yimin of reporter Jiang Qinghua
